added github action script

Signed-off-by: Peter Siegmund <developer@mars3142.org>

.github/workflows/esp32_build.yml

@@ -0,0 +1,20 @@
+name: Thomas the tank engine - Build
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v2
+        with:
+          submodules: "recursive"
+      - name: esp-idf build
+        uses: espressif/esp-idf-ci-action@v1
+        with:
+          esp_idf_version: v5.2
+          target: esp32s3